AC233 Tutorial 6 (Projects Portion)

Tutorial 6 Detailed Review Questions
Chapter 1 to 3
Why is there one main internet layer standard but many subnet standards?

Only 1 internet standard IP because it is concerned with:

End-to-end routing messages ie across multiple subnets
Serve to create a single route between 2 host computers
The only router language is IP

Many subnets standards because:

It is specific to implementation of technology in the network
This gives advantage of flexibility due to diverse choice of i) datalink standard

ii) phy layer standard

How do you think TCP/IP standards will change in the future?

Change will stem from growing traffic and demand for speed and security
To manage distributed denial of service issues
New standards will be 'smart' and recognise 'tags' on packets to divert such packets to faster and more secure routes

Trace the steps begin when your webserver issues a HTTP-Response-PDU and end when the browser receives the requested file.

Application layer-> tpt layer-> internet-> data->routers…..->data->internet->tpt->application->browser

If you type a URL and your browser tells you that the host could not be found, what might have gone wrong?

Wrong url
Non existent url
Heavy traffic/router failure/site blocked by server/connection timeout(not enuf proxy servers)

What is the relationship between distance travelled and noise errors?

The longer the distance the higher the likelihood of noise errors because of:

> attenuation, > distortion, > propagation effect

What is the relationship between bit rate and noise errors?

Larger bit rate increases noise errors.

Difference between broadband and baseband? What is the economic difference?

Broadband is faster because it has multiple channels instead of one channel as in baseband. The packets are all serialized for easier transmission.

Economic factors to consider fixed cost(fc) versus variable costs(vc).

With a higher capacity broadband is > economic as multiple wires are fully utilised.

With a lower capacity baseband is > economic as less wires out to waste

Conduits are fc. Wires are vc.

AC233 Tutorial 6 (Projects Portion)

Chapter 1

Qn 1New and impt information:

720 milln Internet users in 2005 à exploit the possibilities
ISP's to improve service in log-on speeds
Demand for Networking + Internet Skills

Qn 2 Standards for XML

Mission Statement

The mission of this working group is to develop an XML compliant syntax used for representing the signature of Web resources and portions of protocol messages (anything referencable by a URI) and procedures for computing and verifying such signatures. This is a joint Working Group of the IETF and W3C. W3C is hosting the email list and WG site publically in accordance with IETF procedure. Please see the Charter for further information on the constitution of this WG.

Deliverables

This working group will deliver the following:

W3C Working Draft (Informational RFC) further specifying the requirements and dependencies for the remaining deliverables.

W3C Recommendation (Proposed Standard RFC) that defines a highly extensible XML syntax and processing used for associating a signature with XML data without semantic specification but having provisions for the inclusion of such specification.

W3C WD/NOTE (Proposed Standard/Informational RFC) on signature manifest/package semantics labeling and, if appropriate, an additional (small) set of signature semantics in a schema definition (XML/RDF) or link type definition (XLink).

W3C NOTE (Informational RFC) documenting a set of test cases for interoperability testing and a report on interoperability results.

If appropriate, charters for further work.

Adapter Address : 44-45-53-54-00-00

IP Address : 165.21.205.61

Subnet Mask : 255.255.0.0

Default Gateway/Router : 165.21.205.61

Qn. 3 and 4

Can't do number of host estimation and can't find "neotrace.exe" respectively.

Chapter 2

Qn. 1

HTTP 1.1 opens a TCP connection at the beginning of the first HTTP request-response cycle and keeps the connection open until the last HTTP request-response cycle is complete.

Avoiding open and close processes for each HTTP request-response cycle reduces the number of TCP-PDUs that must be generated overall. HTTP 1.1 is becoming increasingly common.

Qn 2

Internet standards are issued as Requests for Comment (RFCs).

1213 Management Information Base for Network Management of TCP/IP-based internets: MIB-II
RFC 1213 is obsoleted or updated by 2011, 2012, 2013 (dated Nov 1996)

Chapter 3

DSL Modem Standard

The International Telecommunications Union-Telecommunications Standards Sector (ITU-T) is currently finalizing a asynchronous digital subscriber line (ADSL) modem standard. The standard is G.lite (officially, G.922.2).G.lite will offer a download speed of 1.5 Mbps. Although this is slower than cable modem speeds, this capacity is not shared, as cable modem capacity is.

In addition, a telephone channel will be multiplexed with the data channel, so that if you have a digital subscriber line, you will not need a separate telephone line.

One advantage of G.lite is that it should not require someone from the telephone company to come out to install the modem. G.lite modems should come installed with some new PCs and should be able to be user-installable at home.

America Online is also planning to offer high speed access for a premium of $20 per month. The service will run at 640 kbps downstream.

AOL users will have to purchase DSL modems at perhaps $100 to $200.

Cable Modem Standard

The cable industry is developing a standard for cable modems. This is the Data Over Cable System Interface Specification (DOCSIS).

Wireless Internet Access at 25 Mbps

Two carriers are testing 25 Mbps wireless Internet access technology. This will not only greatly increase speed. It will also allow notebook computers to participate fully in Internet access.

Product Model, Price, Vendor Name,

V.34 modem IBM EXTERNAL V.34 DATA FAX MODEM/ $479.99/ IBM Networking

V.90 modem, internal Smart One 56K V.90 Int PC Modem $29.99 after reb/$49.99/ Best Data Products

V.90 modem, external Smart One USB 56K V.90 Modems/ $89.99/ Best Data Products

V.90 modem, PC Card 3Com 56K V.90 Cell Mob PC Card Xjack/$179.99/3Com
ISDN modem International PC Card 56K Modem with ISDN/ $299.00/ IBM PC Company
Cable modem (if you can find one)
ADSL modem (if you can find one)
UTP wiring